凡纳滨对虾6个国内群体的遗传背景分析

Genetic Background Analysis of Six Groups of White Shrimp Litopenaeus vannamei in China Using SSR Markers

本研究选取了来自国内6个不同育苗场的凡纳滨对虾(Litopenaeus vannamei)群体,对8个SSR位点的基因型信息进行分析。结果显示,观察等位基因数(Na)平均值为3.67~9.33,有效等位基因数(Ne)平均值为2.20~5.67,观察杂合度(Ho)平均值为0.12~0.71,期望杂合度(He)平均值为0.41~0.81,多态性信息含量(PIC)平均值为0.36~0.76。聚类分析结果显示,来自于同一个育苗场的对虾聚在一个分支。不同品牌来源的对虾分别聚在几个不同分支。6个群体间的遗传一致度为0.4229~0.8265,遗传距离为0.1905~0.8607。遗传分化系数(FST)是0.1837,群体内近交系数(FIS)是0.2514,Ho<He,研究表明,6个群体总的遗传多态性较高,但也提示品牌内不同群体间的遗传距离可能较近,近交情况可能存在。

Controlling the inbreeding level is an important task in animal breeding.Genetic analysis such as genetic diversity and genetic distance estimate could provide information for the artificial selection of animals.In the present study,the genetic information of Pacific white shrimp Litopenaeus vannamei from six different populations in China were analyzed using genotyping data of eight SSR loci.The results showed that the mean Na ranged from 3.67 to 9.33,the mean Ne range from 2.20 to 5.67,the mean Ho ranged from 0.12 to 0.71,the mean He ranged from 0.41 to 0.81,and the mean PIC ranged from0.36 to 0.76.The cluster analysis results showed that the individual shrimps from populations of different companies were clustered in different nodes.The individual shrimps from three hatcheries from the same company were clustered in one node.Among the six populations of L.vannamei,the genetic identity ranged from 0.4229 to 0.8265,and the genetic distance ranged from 0.1905 to 0.8607.The mean value of FST was 0.1837.The FIS value was 0.2514.And the Ho value was smaller than the He value.The results suggested that genetic diversity between L.vannamei from different populations could be high,while,genetic relationship of L.vannamei in populations of the same company might be quite close.There might be an inbreeding phenomenon.